--- a/hotspot/src/share/vm/opto/memnode.hpp Wed May 20 17:06:44 2015 +0200
+++ b/hotspot/src/share/vm/opto/memnode.hpp Thu May 21 13:54:07 2015 +0200
@@ -137,7 +137,33 @@
//------------------------------LoadNode---------------------------------------
// Load value; requires Memory and Address
class LoadNode : public MemNode {
+public:
+ // Some loads (from unsafe) should be pinned: they don't depend only
+ // on the dominating test. The boolean field _depends_only_on_test
+ // below records whether that node depends only on the dominating
+ // test.
+ // Methods used to build LoadNodes pass an argument of type enum
+ // ControlDependency instead of a boolean because those methods
+ // typically have multiple boolean parameters with default values:
+ // passing the wrong boolean to one of these parameters by mistake
+ // goes easily unnoticed. Using an enum, the compiler can check that
+ // the type of a value and the type of the parameter match.
+ enum ControlDependency {
+ Pinned,
+ DependsOnlyOnTest
+ };
private:
+ // LoadNode::hash() doesn't take the _depends_only_on_test field
+ // into account: If the graph already has a non-pinned LoadNode and
+ // we add a pinned LoadNode with the same inputs, it's safe for GVN
+ // to replace the pinned LoadNode with the non-pinned LoadNode,
+ // otherwise it wouldn't be safe to have a non pinned LoadNode with
+ // those inputs in the first place. If the graph already has a
+ // pinned LoadNode and we add a non pinned LoadNode with the same
+ // inputs, it's safe (but suboptimal) for GVN to replace the
+ // non-pinned LoadNode by the pinned LoadNode.
+ bool _depends_only_on_test;
+
// On platforms with weak memory ordering (e.g., PPC, Ia64) we distinguish
// loads that can be reordered, and such requiring acquire semantics to
// adhere to the Java specification. The required behaviour is stored in
@@ -154,8 +180,8 @@
virtual Node* find_previous_arraycopy(PhaseTransform* phase, Node* ld_alloc, Node*& mem, bool can_see_stored_value) const;
public:
- LoadNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *rt, MemOrd mo)
- : MemNode(c,mem,adr,at), _type(rt), _mo(mo) {
+ LoadNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *rt, MemOrd mo, ControlDependency control_dependency)
+ : MemNode(c,mem,adr,at), _type(rt), _mo(mo), _depends_only_on_test(control_dependency == DependsOnlyOnTest) {
init_class_id(Class_Load);
}
inline bool is_unordered() const { return !is_acquire(); }
@@ -166,7 +192,8 @@
// Polymorphic factory method:
static Node* make(PhaseGVN& gvn, Node *c, Node *mem, Node *adr,
- const TypePtr* at, const Type *rt, BasicType bt, MemOrd mo);
+ const TypePtr* at, const Type *rt, BasicType bt,
+ MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest);
virtual uint hash() const; // Check the type
@@ -234,16 +261,15 @@
// which produce results (new raw memory state) inside of loops preventing all
// manner of other optimizations). Basically, it's ugly but so is the alternative.
// See comment in macro.cpp, around line 125 expand_allocate_common().
- virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM; }
-
+ virtual bool depends_only_on_test() const { return adr_type() != TypeRawPtr::BOTTOM && _depends_only_on_test; }
};
//------------------------------LoadBNode--------------------------------------
// Load a byte (8bits signed) from memory
class LoadBNode : public LoadNode {
public:
- LoadBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo)
- : LoadNode(c, mem, adr, at, ti, mo) {}
+ LoadBNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegI; }
virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
@@ -256,8 +282,8 @@
// Load a unsigned byte (8bits unsigned) from memory
class LoadUBNode : public LoadNode {
public:
- LoadUBNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeInt* ti, MemOrd mo)
- : LoadNode(c, mem, adr, at, ti, mo) {}
+ LoadUBNode(Node* c, Node* mem, Node* adr, const TypePtr* at, const TypeInt* ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegI; }
virtual Node* Ideal(PhaseGVN *phase, bool can_reshape);
@@ -270,8 +296,8 @@
// Load an unsigned short/char (16bits unsigned) from memory
class LoadUSNode : public LoadNode {
public:
- LoadUSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo)
- : LoadNode(c, mem, adr, at, ti, mo) {}
+ LoadUSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegI; }
virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
@@ -284,8 +310,8 @@
// Load a short (16bits signed) from memory
class LoadSNode : public LoadNode {
public:
- LoadSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo)
- : LoadNode(c, mem, adr, at, ti, mo) {}
+ LoadSNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegI; }
virtual Node *Ideal(PhaseGVN *phase, bool can_reshape);
@@ -298,8 +324,8 @@
// Load an integer from memory
class LoadINode : public LoadNode {
public:
- LoadINode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo)
- : LoadNode(c, mem, adr, at, ti, mo) {}
+ LoadINode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeInt *ti, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadNode(c, mem, adr, at, ti, mo, control_dependency) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegI; }
virtual int store_Opcode() const { return Op_StoreI; }
@@ -331,15 +357,15 @@
public:
LoadLNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const TypeLong *tl,
- MemOrd mo, bool require_atomic_access = false)
- : LoadNode(c, mem, adr, at, tl, mo), _require_atomic_access(require_atomic_access) {}
+ MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
+ : LoadNode(c, mem, adr, at, tl, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegL; }
virtual int store_Opcode() const { return Op_StoreL; }
virtual BasicType memory_type() const { return T_LONG; }
bool require_atomic_access() const { return _require_atomic_access; }
static LoadLNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
- const Type* rt, MemOrd mo);
+ const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest);
#ifndef PRODUCT
virtual void dump_spec(outputStream *st) const {
LoadNode::dump_spec(st);
@@ -352,8 +378,8 @@
// Load a long from unaligned memory
class LoadL_unalignedNode : public LoadLNode {
public:
- LoadL_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo)
- : LoadLNode(c, mem, adr, at, TypeLong::LONG, mo) {}
+ LoadL_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadLNode(c, mem, adr, at, TypeLong::LONG, mo, control_dependency) {}
virtual int Opcode() const;
};
@@ -361,8 +387,8 @@
// Load a float (64 bits) from memory
class LoadFNode : public LoadNode {
public:
- LoadFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t, MemOrd mo)
- : LoadNode(c, mem, adr, at, t, mo) {}
+ LoadFNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegF; }
virtual int store_Opcode() const { return Op_StoreF; }
@@ -382,15 +408,15 @@
public:
LoadDNode(Node *c, Node *mem, Node *adr, const TypePtr* at, const Type *t,
- MemOrd mo, bool require_atomic_access = false)
- : LoadNode(c, mem, adr, at, t, mo), _require_atomic_access(require_atomic_access) {}
+ MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest, bool require_atomic_access = false)
+ : LoadNode(c, mem, adr, at, t, mo, control_dependency), _require_atomic_access(require_atomic_access) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegD; }
virtual int store_Opcode() const { return Op_StoreD; }
virtual BasicType memory_type() const { return T_DOUBLE; }
bool require_atomic_access() const { return _require_atomic_access; }
static LoadDNode* make_atomic(Node* ctl, Node* mem, Node* adr, const TypePtr* adr_type,
- const Type* rt, MemOrd mo);
+ const Type* rt, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest);
#ifndef PRODUCT
virtual void dump_spec(outputStream *st) const {
LoadNode::dump_spec(st);
@@ -403,8 +429,8 @@
// Load a double from unaligned memory
class LoadD_unalignedNode : public LoadDNode {
public:
- LoadD_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo)
- : LoadDNode(c, mem, adr, at, Type::DOUBLE, mo) {}
+ LoadD_unalignedNode(Node *c, Node *mem, Node *adr, const TypePtr* at, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadDNode(c, mem, adr, at, Type::DOUBLE, mo, control_dependency) {}
virtual int Opcode() const;
};
@@ -412,8 +438,8 @@
// Load a pointer from memory (either object or array)
class LoadPNode : public LoadNode {
public:
- LoadPNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t, MemOrd mo)
- : LoadNode(c, mem, adr, at, t, mo) {}
+ LoadPNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const TypePtr* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegP; }
virtual int store_Opcode() const { return Op_StoreP; }
@@ -425,8 +451,8 @@
// Load a narrow oop from memory (either object or array)
class LoadNNode : public LoadNode {
public:
- LoadNNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t, MemOrd mo)
- : LoadNode(c, mem, adr, at, t, mo) {}
+ LoadNNode(Node *c, Node *mem, Node *adr, const TypePtr *at, const Type* t, MemOrd mo, ControlDependency control_dependency = DependsOnlyOnTest)
+ : LoadNode(c, mem, adr, at, t, mo, control_dependency) {}
virtual int Opcode() const;
virtual uint ideal_reg() const { return Op_RegN; }
virtual int store_Opcode() const { return Op_StoreN; }